/PlayingWithWolverineMarten

Try out Wolwerine, Marten and Event Sourcing

Primary LanguageC#

Playing with Wolverine and Marten

In this repository, I have started putting together some examples of using Wolverine and Marten during my learning process.

Both Wolverine and Marten are part of the "Critter Stack" family of 👤JasperFx tools, they are Open Source projects 📓Jeremy Miller.

  • Wolwerine: Next generation Mediator and MessageBus, it is all about professional messaging
  • Marten: Allows developers to use the PostgreSQL database as a document database and a fully-featured EventStore

They can be used individually as they serve their own purpose, but they can be integrated together to open a new door for neat features (durable Inbox and Outbox messaging).

The solution has the following projects
WolverineHttpWithMarten
  • Web API using WolverineFx.Http for managing Http endpoint routing
  • Using Marten to store a Product entity and DurableInbox for local queue messages in a transaction
  • Apply fluent validation middleware and a custom to load Product entity by id
Worker.Ping
  • Worker service with a few BackgroundService
  • Sending in-process ping-pong messages via local queue
  • Sending PingMessage via RabbitMq and listening for PongMessage (from Worker.Pong)
  • Sending RequestMessage via RabbitMq and require a ResponseMessage via RabbitMq response-queue
Worker.Pong
  • Listening for PingMessage and send a PongMessage via RabbitMq
  • Getting RequestMessage via RabbitMq and send back a ResponseMessage via RabbitMq response-queue
WolverineHttpWithMarten.UnitTest
  • An example of unit testing our work and mocking 2 main components
    • IMessageBus or IMessageContext for Wolverine with the built-in TestMessageContext
    • IDocumentSession for Marten with any framework (Moq, NSubstitute)
WolverineHttpWithMarten.IntegrationTest
  • An example of integration testing the Web API using
    • Alba to spin up Web API in memory using the built-in TestServer
    • Testcontainers to get a new PostgresDB for our test and throw it away at the end
  • You can disable external Wolverine transports to have an isolated environment
  • You can run HTTP requests against you API
  • Wolverine provides you with a built-in mechanism called TrackedSession that ensures certain events/messages are sent out
  • You can trigger any handlers by invoking them from outside and simulate that you received a message from RabbitMQ
  • Using a feature of Marten, you can easily wipe out all data and initialize it again before running all the tests
  • All of these features are extremely good to work with
EventSourcingApi
  • Web API with a few endpoints to operate on Events
  • Example #1: Counter - that we can increase / decrease
    • Simulate parallels access to an event-stream and using AppendExclusive to lock the actual stream
    • Add an inline projection to update the counter
    • Add an async IProjection to simulate sending events to an external service (handle intermittent exceptions with retries)
    • Add a MultiStreamProjection to summarize events for each user
SagaApi
  • Keeping it simple, and using Web API endpoints to manage Saga state instead of external transports
  • EmailConfirmation process as an example

Personal opinion:

  • Both Wolverine and Marten are more than awesome, I enjoy working with them
  • They looks easy to use, but they can become somewhat larger animals as you discover the itsy-bitsy details
  • The documentation is very good and sufficient length to keep you occupied
  • Unit and Integration tests are like a dream with Alba
  • Wolverine is not just yet another messaging framework, it also encourages you to think differently while building a system
Resources - Wolwerine and Marten
Resources - Wolwerine
Resources - Marten